8．"Old wives tales"are beliefs passed down from one generation to another，For example，most of us remember our patents'telling us to eat more of certain foods or not to do certain things．Is there any truth in these teachings？Some of them agree with present medical thinking，but others have not passed the test of time
Did your mother ever tell you to eat your carrots because they are good for your eyes？Scientists now report that eating carrots can help prevent a serious eye disease called macular degeneration Eating just one carrot a day can reduce the possibility of getting this disease by 40%．Garlic（蒜）is good for you，too．It can kill the type of virus that causes colds．
Unfortunately，not all of Mom's advice passed the test of medical studies．For example，generations of children have been told not to go swimming within an hour after eating．But research suggests that there is no danger in doing so．Do sweets cause tooth problems？Well，yes and no．sticky sweets made with grains tend to cause more problems than sweets made with simple sugars．
Even though science can tell us that some of our traditional beliefs don't hold water，there is still a lot of truth in the old wives'tales，After all，much of this knowledge has been accumulated （积累） from thousands of our traditional beliefs don't hold water should respect this body of knowledge even as research for clear scientific support to proven it true or false
48．Which of the following is TRUE according to the text？B
A Eating garlic is good for our eyes
B Sticky sweets are damaging to our teeth
C Swimming after a meal is dangerous．
D Carrots prevent people from catching colds
49．The author develops the third paragraph mainlyD．
A．by cause and effects
B．by order in space
C．by order in time
D．by examples
50．The phrase"hold water"in the last paragraph most probably means"A"
A．to be believable
B．to be valuable
C．to be admirable
D．to be smtable
51．What is the author's attitude toward"old wives'tales"in the text？B
A．So objective
B．Objective
C．Dissatisfied
D．Curious．
